FAIR VALUE DISCLOSURES - Schedule of Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Income	Net Income	Net Income	Net Income
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 5,492,768	$ 8,250,460	$ 5,558,633	$ 7,632,487
Purchases	225,000	852,000	275,000	1,539,650
Settlements	(281,132)	(1,258,093)	(345,522)	(1,400,530)
Allowance for Losses	30	9	58	45
Realized and unrealized (losses)/gains included in Income	(6,546)	(101,929)	(87,256)	(8,228)
Unrealized gains/(losses) included in Other Comprehensive Income	(4,906)	27,679	24,301	6,702
Ending Balance	5,425,214	7,770,126	5,425,214	7,770,126
Available-for-sale securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,281	19,031	19,082	19,027
Purchases	0	0	0	0
Settlements	0	0	0	0
Allowance for Losses	1	1	2	5
Realized and unrealized (losses)/gains included in Income	0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income	196	0	394	0
Ending Balance	19,478	19,032	19,478	19,032
Floating rate auction-rate certificates backed by Government guaranteed student loans | Floating interest rate | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,281	19,031	19,082	19,027
Purchases	0	0	0	0
Settlements	0	0	0	0
Allowance for Losses	1	1	2	5
Realized and unrealized (losses)/gains included in Income	0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income	196	0	394	0
Ending Balance	19,478	19,032	19,478	19,032
Farmer Mac Guaranteed Securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,466,688	8,225,454	5,532,479	7,607,226
Purchases	225,000	852,000	275,000	1,539,650
Settlements	(281,004)	(1,257,854)	(345,136)	(1,399,673)
Allowance for Losses	29	8	56	40
Realized and unrealized (losses)/gains included in Income	(6,460)	(101,872)	(87,155)	(8,530)
Unrealized gains/(losses) included in Other Comprehensive Income	(5,102)	27,679	23,907	6,702
Ending Balance	5,399,151	7,745,415	5,399,151	7,745,415
Farmer Mac Guaranteed Securities | Level 3 | Recurring | AgVantage Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,457,197	8,217,420	5,522,712	7,599,379
Purchases	225,000	852,000	275,000	1,539,650
Settlements	(280,833)	(1,257,413)	(344,788)	(1,398,799)
Allowance for Losses	29	8	56	40
Realized and unrealized (losses)/gains included in Income	(6,460)	(101,872)	(87,155)	(8,530)
Unrealized gains/(losses) included in Other Comprehensive Income	(5,092)	27,667	24,016	6,070
Ending Balance	5,389,841	7,737,810	5,389,841	7,737,810
Farmer Mac Guaranteed Securities | Level 3 | Recurring | Farmer Mac Guaranteed USDA Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9,491	8,034	9,767	7,847
Purchases	0	0	0	0
Settlements	(171)	(441)	(348)	(874)
Allowance for Losses	0	0	0	0
Realized and unrealized (losses)/gains included in Income	0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income	(10)	12	(109)	632
Ending Balance	9,310	7,605	9,310	7,605
USDA Securities: | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,066	1,405	1,241	1,767
Purchases	0	0	0	0
Settlements	(43)	(48)	(216)	(435)
Allowance for Losses	0	0	0	0
Realized and unrealized (losses)/gains included in Income	3	(9)	1	16
Unrealized gains/(losses) included in Other Comprehensive Income	0	0	0	0
Ending Balance	1,026	1,348	1,026	1,348
Guarantee and commitment obligations: | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,733	4,570	5,831	4,467
Purchases	0	0	0	0
Settlements	(85)	(191)	(170)	(422)
Allowance for Losses	0	0	0	0
Realized and unrealized (losses)/gains included in Income	(89)	(48)	(102)	286
Unrealized gains/(losses) included in Other Comprehensive Income	0	0	0	0
Ending Balance	5,559	4,331	5,559	4,331
Guarantee and commitment obligations: | Level 3 | Recurring | Guarantee Asset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,733	4,570	5,831	4,467
Purchases	0	0	0	0
Settlements	(85)	(191)	(170)	(422)
Allowance for Losses	0	0	0	0
Realized and unrealized (losses)/gains included in Income	(89)	(48)	(102)	286
Unrealized gains/(losses) included in Other Comprehensive Income	0	0	0	0
Ending Balance	$ 5,559	$ 4,331	$ 5,559	$ 4,331